EP0464720B1

EP0464720B1 - Drive device of slide door

Info

Publication number: EP0464720B1
Application number: EP91110785A
Authority: EP
Inventors: Soushichi c/o Ohi Seisakusho Co. Ltd. Koura; June c/o Ohi Seisakusho Co. Ltd. Yamagishi; Masaichi c/o Ohi Seisakusho Co. Ltd. Moriya; Hirotaka c/o Ohi Seisakusho Co. Ltd. Nishizima
Original assignee: Ohi Seisakusho Co Ltd
Current assignee: Ohi Seisakusho Co Ltd
Priority date: 1990-06-29
Filing date: 1991-06-28
Publication date: 1997-09-03
Anticipated expiration: 2011-06-28
Also published as: US5168666A; JPH0749746B2; EP0464720A1; ES2106746T3; JPH0462284A

Description

The present inventions relates to a drive device for driving a slide door as defined in the preamble portion of claim 1. Moreover, the present invention relates to a slide door operating system for a vehicle according to the preamble portion of claim 16. These devices can be used with motor vehicles.
A drive device as mentioned above is known from EP-A-0 358 874, whereas the above-mentioned slide door operating system is known from GB-A-2 168 424.
From EP-A-0 358 874, which discloses the features of the preamble of claim 1, a slide door is known which is driven by a motor via a drive roller and an endless wire having a circular cross-section. The endless wire runs alongside an outer surface of the vehicle with one run arranged vertically above the other. Further, the wire is diverted at an angle of about 90° by two spring actuated levers in the vicinity of a drive pulley at the rear end. The front end of the endless wire is looped around a driven pulley having a substantially vertical axis of rotation, whereas the axis of rotation of the drive pulley is substantially horizontal. Because of the rather complicated path of the endless wire, rather strong springs are necessary for tensioning the endless wire. Consequently, a strong force will be required for pushing the door by hand since a user has to overcome the torque of the motor and the inertial force of the door at the same time. A clutch is provided between the motor and the drive pulley to separate the motor from the drive pulley to allow the door to be opened by hand.
From GB-A-2 168 424, which discloses the features of the preamble of claim 16, an opening and closing mechanism for a slide door including a door lock mechanism is known wherein one cable is provided for opening the door and another cable is provided for closing the door and for actuating the door lock.
In order to further clarify the object of the present invention, another conventional drive device of an automotive slide door will be described, which is disclosed in JP-A-61-36480.
The conventional door drive device comprises generally a drive cable which extends around a given oval path defined beneath a vehicle floor, several pulleys around which the drive cable is put, a drive drum which has both ends of the drive cable wound therearound, and a reversible motor which drives the drive drum. An electromagnetic clutch and a speed reduction gear are arranged between the drive drum and the motor. The drive cable is fixed to the door at a portion.
Thus, when, with the clutch being engaged, the motor is energized to run in a given direction, the drive drum is rotated to drive the drive cable. With this, the door is moved forward or rearward.
The reason of using the clutch between the drive drum and the speed reduction gear is to facilitate a movement of the door effected by manual labor. That is, when the door drive device gets out of order, the clutch is switched to assume its disengaged condition. Under this condition, the rotation of the drive drum carried out by manual movement of the door does not affect the speed reduction gear and the motor. If the manual movement of the door is carried out with the clutch kept engaged, a great resistance against the movement is produced by these devices.
However, the above-mentioned conventional door slide device has the following drawbacks due to its inherent construction.
First, usage of the electromagnetic clutch causes a bulky, heavy and highly-costed construction of the door drive device.
Second, combining the door drive device with other door control devices such as those disclosed in JP-A-1-164647 is difficult, which devices are an automatic door closure which forces to shift the door to a fully closed latched position when the door comes to a half-latch position and a door lock canceller which forces to cancel the latched condition of the closed door prior to starting of opening movement of the door. In fact, it is difficult to obtain timed operations of these control devices. For example, if the door drive device starts to operate prior to cancelling of the latched condition of the door, a great load is applied to the cable, the speed reduction gear and the motor. Furthermore, if, upon closing of the door, the speed at which the door is shifted by the door closure and the speed at which the door is moved by the door drive device are not matched, an excessive load is applied to both the door closure and the door drive device.
Thus, the object of the present invention is to provide a drive device for a slide door and a slide door operating system, including an endless flexible means connected to the door and arranged between a drive pulley and a driven pulley, allowing the door to be opened or closed by hand even if a power source, for example an electric motor is coupled to the drive pulley and to facilitate cooperation with a door lock mechanism.
According to the present invention, this problem is solved by a drive device for driving a slide door according to claim 1 and a slide door operating system according to claim 16.
Further advantageous embodiments of the invention are laid down in the subclaims.
Further advantages of the present invention will become apparent from the following description of a preferred embodiment when taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a partial perspective view of a motor vehicle to which a door drive device according to the present invention is practically applied;
Fig. 2 is a partially cut plan view of the door drive device;
Fig. 3 is a sectional view taken along the line III-III of Fig. 2; and
Fig. 4 is a sectional view taken along the line IV-IV of Fig. 2.

In the following, a preferred embodiment of the door drive device according to the present invention will be described in detail with reference to the drawings.
In Fig. 1, there is shown a motor vehicle to which the present invention is practically applied. In this drawing, denoted by numeral 1 is a body of the vehicle which has a door opening (no numeral) at one side wall. The door opening has a horizontal flat bottom portion which serves as a step for passengers. Denoted by numeral 2 is a lower guide rail which is secured to the vehicle body 1 below the step of the door opening and extends substantially horizontally.
As is best seen from Fig. 2, the lower guide rail 2 has a front portion gradually curved toward the inside of the vehicle body 1.
Although not shown in the drawings, an upper rail is secured to an upper portion of the door opening and a middle guide rail is secured to the side wall of the vehicle body 1 in the rear of the door opening. These two rails extend substantially horizontally.
Denoted by numeral 3 is a slide door which is guided by the upper, middle and lower guide rails in such a manner that after being shifted laterally outward from its full-closed position, the door 3 is moved rearward in parallel with the side wall of the vehicle body 1.
The door 3 has at its front lower portion a horizontal bracket 4 which extends toward the interior of the vehicle body. The bracket 4 is equipped at its leading end with both vertical and horizontal rollers 5 and 6 (see Fig. 2) which are rotatably engaged with and guided by the lower guide rail 2. The arrangement of these parts may be well understood from Fig. 4.
As is seen from Figs. 1 and 3, mounted to the lower surface of the step of the door opening is an elongate case 7 of a door drive mechanism "A". For this mounting, the case 7 has at is upper portion several mounting lugs 7a which are bolted to the step. The bottom wall of the case 7 is designated by numeral 7b.
Within the case 7, there is installed a drive unit 8 which is located at a front portion of the case 7.
As is seen from Figs. 3 and 4, the drive unit 8 comprises a housing 9 and a lid 10 which covers an upper opening of the housing 9. Within the housing 9, there is installed a reversible electric motor 11 whose output shaft 11a extends vertically. A first smaller spur gear 12 is secured to the output shaft 11a to rotate therewith. Operatively engaged with the first gear 12 is a second larger spur gear 13a which is rotatably held by and between the housing 9 and the lid 10. A third smaller spur gear 13b is secured to a lower side of the second gear 13a to rotate therewith. Operatively engaged with the third gear 13b is a fourth larger spur gear 15 which is coaxially secured to a vertically extending output shaft 14. In order to support the second, third and fourth gears 13a, 13b and 15, the housing 9 has a thicker supporting part 9a which is positioned above the bottom wall 7b of the case 7. Designated by numeral 19 is a bearing member which has a blind bore 19a into which a lower end of the output shaft 14 is rotatably received. The bearing member 19 has two walls 19b and 19c by which the thicker supporting part 9a is supported.
The first gear 12, the second gear 13a, the third gear 13b and the fourth gear 15 constitute a speed reduction gear 16.
The output shaft 14 has a lower portion to which a drive pulley 17 is coaxially secured by means a key 18. The cylindrical outer surface of the drive pulley 17 is formed with evenly spaced splines or teeth 17a for the purpose which will be clarified hereinafter.
Referring back to Fig. 1, a driven pulley 20 is further installed at a rear portion of the case 7, which pulley has a vertically extending rotation shaft 21. Similar to the drive pulley 17, the cylindrical outer surface of the driven pulley 20 is formed with evenly spaced splines or teeth 20a.
Around the drive and driven pulleys 17 and 20, there is slackly put an endless belt 22 which has a toothed inner surface operatively meshed with the teeth 17a and 20a of the pulleys 17 and 20. The teeth of the belt 22 are denoted by numeral 22a.
As is seen from Figs. 2 and 4, one portion of the belt 22 is fixed to a belt holding bracket 23 which extends from the door 2. More specifically, the belt holding bracket 23 has a base portion 23b secured to the bracket 4 through bolts 24 and nuts and extends horizontally under the bracket 4 and projects into the case 7 through a longitudinally extending slot 25 formed in an outside wall of the case 7.
As is best seen from Fig. 4, the projecting end 23a of the belt holding bracket 23 is vertically raised for tightly grasping the belt 2.
As is well seen from Figs. 1 and 2, front and rear tensioners are installed in the case 7 to tension the belt 22 thereby to take up the slack of the belt 22. These front and tensioners are arranged to tension outside and inside parts of the belt 22, respectively.
It is to be noted that the outside part of the belt 22 means one half part of the belt 22 which extends along an outside way between the drive and driven pullyes 17 and 20, while the inside part of the belt 22 means the other half of the belt 22 which extends along an inside way between the two pulleys 17 and 20.
As is seen from Fig. 2, each tensioner comprises a vertically extending pivot shaft 27, an arm 26 having a base portion pivotally connected to the pivot shaft 27, a tension roller 28 rotatably mounted to a leading end of the arm 26 through a pin 29, and a spring 31 for biasing the arm 26 in a direction to press the tension roller 28 against the toothed inner surface of the belt 22. The spring 31 has one end hooked to a projection 26a of the arm 26 and the other end hooked to a projection 30 of the bottom wall 7b of the case 7.
Designated by numeral 32 is a stopper formed on the bottom wall 7b of the case 7, by which an excessive pivoting of each arm 26 toward the belt 22 is restricted. An excessive pivoting of the arm 26 in the other direction, that is, in a direction away from the belt 22, is restricted by the projection 30.
As is seen from Fig. 2, the front tensioner is so arranged that when the brackets 4 and 23 come to a junction zone 2c between straight and curved portions 2a and 2b of the guide rail 2, the belt 2 is separated from the tension roller 28, and when the brackets 4 and 23 are moved forward or rearward away from the junction zone 2c of the guide rail 2, the belt 22 becomes into contact with the tension roller 28. With this arrangement, the raised inside end of the belt holding bracket 23 is prevented from contacting the tension roller 28.
While, the rear tensioner is so arranged as to tension the belt 22 constantly.
As is seen from Fig. 2, a guide roller 33 is arranged between the drive pulley 17 and the rear tensioner, which constantly contacts the outer surface of the belt 22.
Referring back to Fig. 1, within the door 3, there are installed a known door lock 35, a known lock canceller 36 and a known door closure 37, which are disclosed in the above-mentioned Japanese Patent First Provisional Publication No. 1-164647. Furthermore, an electric connector is employed, which comprises a body-mounted connector part 38 and a door-mounted connector part 39. When, under closing movement, the door 3 comes to a so-called "power feeding position" just before a half-latch position, the door-mounted connector part 39 is brought into engagement with the body-mounted connector part 38, so that thereafter electric feeding from a battery on the vehicle body to the electric devices in the door 3 becomes available.
In the following, operation of the door drive device of the present invention will be described with reference to the drawings.
For ease of understanding, the description will be commenced with respect to a condition wherein the door 3 is fully closed and latched.
Under this condition, the brackets 4 and 23 and the endless belt 22 assume the positions as illustrated by solid lines in Fig. 2. The positions of the brackets 4 and 23 in this condition are denoted by reference "X1". As shown, each tension roller 28 is pressed against the belt 22 to softly tension the same with arm 26 abutting against the stopper 32.
When now a door open control switch (not shown) installed in a driver's room is manipulated to take ON position, the electric power of the battery is fed to the lock canceller 36 through the connector (38 and 39). Thus, the locked condition of the door lock 35 is cancelled.
Upon this, the door 3 is somewhat shifted outward due to the restoring force of a door seal and the biasing force applied to a latch plate of the door lock 35. In response to this outward shifting of the door 3, the portion of the belt 22 which is fixed to the bracket 23 is somewhat moved rearward. However, this rearward movement of the portion is quickly absorbed by the entire of the belt 22 by the work of the belt tensioners.
When thereafter the motor 11 is energized to run in a certain direction, the drive pulley 17 is rotated in a counterclockwise direction in Fig. 2.
However, due to the meshed engagement between the drive pulley 17 and the belt 22 and due to the softly tensioned condition of the belt 22, the rotation of the drive pulley 17 does not induce an instant movement of the door 3 in the door opening direction. That is, at a first stage, the rotation of the drive pully 17 is used for only eliminating the slack of the belt 22. During this slack elimination, the two tensioners are gradually pivoted toward their inoperative positions as illustrated by phantom lines.
When, due to elimination of the slack, the belt 22 becomes highly tensioned, the rotation of the drive pulley 17 induces a rearward movement of the belt holding bracket 23. Thus, the door 3 is moved rearward.
It is to be noted that the time lag taken when the door 3 is actually moved after starting of the drive pulley 17 is quite advantageous in operating the other door controllers.
For example, even if the lock cancelling operation of the lock canceller 36 is somewhat delayed, the delayed movement of the door 3 by the belt 22 can compensate such mis-timed operation of the lock canceller 36.
This means that the motor 11 for the door drive device can be started at the same time as or somewhat prior to the operation of the lock canceller 36.
As is known to those skilled in the art, simultaneous energization of two devices (viz., the motor 11 and lock canceller 36) is easily controlled.
Furthermore, if, after starting of the motor 11, the lock canceller 36 is actuated during the time when the slack of the belt 22 is being decreased, the restoring force of the door seal and the biasing force applied to the latch plate of the door lock 35 can be effectively used as an initial force for shifting the door 3 laterally outward from the full-closed position.
When the door 3 is then moved rearward slightly from the laterally outward shifted position, the outside part of the belt 22 becomes detached from the front tensioner. It is to be noted that, under this condition, the stopper 32 stops an excessive pivoting of the arm 26 toward the belt 22.
When then the door 3 is moved rearward to a slightly open position where the horizontal bracket 4 is positioned beside the junction zone 2c of the guide rail 2 as illustrated by a phantom line "X2" of Fig. 2, the projecting end 23a of the belt holding bracket 23 is positioned away from the tension roller 28 of the front tensioner, as shown.
When then the door 3 comes to a position where the horizontal bracket 4 is positioned at the straight portion 2a of the guide rail 22 as illustrated by a phantom line "X3" of Fig. 2, the outside part of the belt 22 becomes in contact with the tension roller 28 of the front tensioner. Thereafter, the contact between the tension roller 28 of the front tensioner and the belt 22 is kept until the bracket 4 comes to the position "X4" of Fig. 2 where the door 3 assumes its full-open position.
When the door 3 thus comes to the full-open position, a limit switch (not shown) for sensing the full-open condition of the door 3 is operated to stop energization of the motor 11. While, when, during movement of the door 3 toward the full-open position, the door open control switch is turned OFF, energization of the motor 11 is stopped and thus the door 3 is forced to stop at a half-open position.
When the door 3 stops at the full-open position or the half-open position, the arm 26 of each tensioner is forced to pivot in a clockwise direction in Fig. 2 by the force of the spring 31 thereby to apply a suitable tension to the belt 22. Thus, slack of the belt 22 is taken up or eliminated. During this, the drive pulley 17, the speed reduction gear 16 and the output shaft 11a of the motor 11 may be somewhat driven by the tensioning force produced by the front and rear tensioners.
When, with the door 3 assuming the full-open position or the half-open position, a door close control switch (not shown) positioned beside the above-mentioned door open control switch is manipulated to take ON position, the motor 11 is energized to turn in a reversed direction and thus the drive pulley 17 is rotated in a clockwise direction in Fig. 2.
At a first stage, the rotation of the drive pulley 17 is used for eliminating the slack of the belt 22. During this slack elimination, the two tensioners are gradually pivoted toward their small-angled positions as illustrated by the phantom lines.
When, due to elimination of the slack, the belt 22 becomes highly tensioned, the clockwise rotation of the drive pulley 17 induces a forward movement of the belt holding bracket 23. Thus, the door 3 is moved forward.
When the door 3 comes to the power feeding position just before the half-latch position, the door-mounted connector part 39 is brought into engagement with the body-mounted connector part 38, and thus power feeding from the battery in the vehicle body to the door closure 37 in the door 3 becomes available. When then the door 3 comes to the half-latch position wherein the latch plate of the door lock 35 is hafly latched with the striker of the vehicle body, the door closure 37 becomes energized. Thus, the latch plate of the door lock 35 is forced to pivot into its full-latched position forcing the door 3 to move to the full-closed latched position.
It is to be noted that the movement of the door 3 from the half-latch position to the full-closed latched position is achieved by both the motor 11 of the door drive device and the door closure 37. Thus, this movement is assuredly carried out.
It is further to be noted that even when the speed at which the door is shifted from the half-latch position to the full-closed latched position by the door closure 37 is greater than the speed at which the door is shifted by the motor 11 of the door drive device, such mismatched operation can be compensated by having the belt 22 slackened between the drive pulley 17 and the belt holding bracket 23.
When, with the door 3 assuming the full-open position or the half-open position, a manual labor is applied to the door 3 for the purpose of moving the door in the closing direction, only the door 3 and a part of the belt 22 are moved at a first stage.
That is, at the first stage, the closing movement of the door 3 is used for eliminating the slack of the belt 22 tensioned by the rear tensioner. More specifically, as the first stage, the closing movement of the door 3 does not induce a movement of the entire of the belt 22 until the slack of the belt 22 is eliminated.
When the slack of the belt 22 is eliminated and thus belt 22 becomes highly tensioned by the continued closing movement of the door 3, the drive pulley 17, the speed reduction gear 16 and the output shaft 11a of the motor 11 are driven by the movement of the door 3.
Accordingly, an initial movement of the door 3 by manual labor in the door closing direction is easily carried out with a light force. That is, just at the time when the closing movement of the door 3 becomes to have a sufficient inertial force, the drive pulley 17, the speed reduction gear 16 and the output shaft 11a of the motor 11 are driven by the movement of the door 3.
It is to be noted that a load applied to the door 3 when these three devices 17, 16 and 11 are driven produces a suitable check against the closing movement of the door 3 and thus the manual closing movement of the door 3 is carried out with a comfortable operation feeling.
When, with the door assuming the full-closed latched position, it is needed to open the door 3 with a manual labor, a door handle (not shown) of the door 3 is manipulated to cancel the locked condition of the door lock 35. Upon this cancellation, the door 3 is somewhat shifted laterally outward due to the restoring force of the door seal. Thus, if this outward shifting of the door 3 is timely used, a subsequent opening movement of the door 3 is easily carried out with a light force. This easy movement of the door 3 in the opening direction is achieved irrespective of whether the slack of the belt 22 has been present or not before the movement of the door 3.
If desired, the following modifications may be employed in the invention.

(1) In place of the above-mentioned toothed belt 22, wire, chain and the like can be used.
(2) One or more than two tensioners can be used for tensioning the belt 22.
(3) In addition to the tensioners of the above-mentioned type, various types of tensioners are usable. One of them may be a type in which a spring biased tension roller is slidably held on a fixed holder which extends perpendicular to the path of the belt 22.

In the following, advantages of the present invention will be described.

(a) In the invention, there is no need of using an expensive electromagnetic clutch in the door drive device. That is, the output shaft 11a of the motor 11 and the belt 22 are constantly connected. Thus, the door drive device of the present invention can have a simple, compact, light-weight and low-costed construction.
(b) Because the belt 22 is put around the drive and driven pulleys 17 and 20 with a suitable slack, the initial opening or closing movement of the door 3 by manual labor is easily carried out with a light force as has been described hereinabove. That is, due to provision of the slack, the driving of the drive pulley 17, the speed reduction gear 16 and the output shaft 11a of the motor 11 by the manual movement of the door 3 is not effected until the movement of the door 3 has a sufficient inertial force.
(c) In case wherein the door drive device of the invention is used in combination with the door closure and the door lock canceller in the above-mentioned manner, mis-timed operations of these devices can be compensated due to provision of the slack of the belt 22. Thus, these devices are prevented from being applied with excessive load.

Claims

A drive device for driving a slide door (3) of a vehicle, in particular a motor vehicle, comprising guide means (2) for guiding said slide door (3) along a predetermined path, first and second pulleys (17, 20) arranged at spaced positions of the vehicle body, a flexible endless means (22) put around said first and second pulleys (17, 20) with a slack, and having a portion (23a) connected to said slide door (3) by connecting means, drive means (8) for driving said first pulley (17), and tensioning means mounted on the vehicle body between the first and second pulleys (17, 20) for guiding the movement of said flexible endless means (22) around said pulleys (17, 20), including biasing means biasing said tensioning means towards said flexible endless means (22) in a manner to eliminate said slack, characterized in that the flexible endless means (22), the pulleys and the tensioning means are arranged in one plane and the drive means and the first pulley (17) are constantly connected such that separation of them never occurs.
Drive device according to claim 1, characterized in that said drive means (8) comprises an electric motor (11), and a speed reduction gear (12, 13, 14, 15) powered by said electric motor (11), said speed reduction gear (12, 13, 14, 15) having an output shaft (14) by which said first pulley (17) is driven, while the output shaft (lla) of the motor (11) is positively connected or integral with the input shaft of the speed reduction gear (12, 13, 14, 15).
Drive device according to claim any of claims 1 or 2, characterized by a flat elongated case (7) accommodating said drive means (8), pulleys (17, 20) endless flexible means (22) and tensioning means, arranged substantially in parallel to said guide means (2).
Drive device according to one of claims 1 to 3, characterized in that the axes of rotation of said pulleys (17, 20) extend vertically.
Drive device according to one of claims 1 to 4, characterized in that said tensioning means are arranged in the space encircled by the flexible endless means (22).
Drive device according to one of claims 1 to 5, characterized in that each of said first and second pulleys (17, 20) and the flexible endless means (22) are arranged to have a meshed engagement therebetween.
Drive device according to claim 6, characterized in that each of said first and second pulleys (17, 20) is provided with a cylindrical outer surface having a plurality of teeth, and that said flexible endless means is an endless belt (22) which has a toothed inner surface operatively meshed with the teeth of said first and second pulleys (17, 20).
Drive device according to claim 7, characterized in that said tensioning means includes at least one tensioner, each comprising a tension roller (28) having a cylindrical outer surface for contacting the toothed inner surface of the endless belt (22), and said biasing means for biasing and pressing said tension roller (28) against said toothed inner surface of said belt.
Drive device according to claim 8, characterized in that said biasing means comprises an arm (26) mounted to said case (7), at one end rotatably holding said tension roller (28), and a spring (31) biasing said arm (26) in a direction to press said tension roller (28) against said endless flexible means (22).
Drive device according to claim 9, characterized by a stopper (32) delimiting the movement of said arm (26) to restrict tension applied to said flexible endless means (22) by said biasing means via said tension roller (28).
Drive device according to one of claims 1 to 10, characterized in that said endless flexible means (22) is connected to said slide door (3) by means of a bracket (4, 23) which has one end fixed to said slide door (3) and another end which tightly grasps a portion (23a) of said flexible endless means (22).
Drive device according to claim 11, characterized in that said guide means comprises a guide rail (2) which includes straight and curved portions (2a, 2b) which are integrally connected at a junction zone (2c) for guiding said bracket (4, 23) while at least one of said tensioning means is positioned near said junction zone (2c).
Drive device according to claim 12, characterized in that said tensioning means comprises a front tensioner which is arranged such that when the bracket (4, 23) passes the junction zone (2c), the flexible endless means (22) is separated from the front tensioner.
Drive device according to one of claims 1 to 13, characterized in that said tensioning means comprises two tensioners for tensioning said flexible endless means (22).
Drive device according to one of claims 1 to 14, characterized by a guide roller (33) for guiding the movement of said endless flexible means (22).
Slide door operating system for a vehicle, in particular a motor vehicle, comprising
a door lock (35) mounted in the slide door (3), said door lock having a latch plate which is engageable with a striker of a vehicle body to achieve a latched condition of the slide door;

a door closure (37) which shifts the slide door (3) to its fully closed latched position when the slide door (3) comes to a half-latched position, a lock canceller (36) which cancels the locked condition of said door when energized and

a drive device for driving the slide door (3), the drive device having guide means for defining in the vehicle body a way along which the slide door moves,
characterized in that said drive device comprises
first and second pulleys (17, 20) arranged at spaced positions on the vehicle body (1),

a flexible endless means (22) put round said first and second pulleys (17, 20) with a slack, and having a portion (23a) connected to said slide door (3) by connecting means,

drive means (8) drivingly connected to said first pulley (17), and

tensioning means mounted on the vehicle body between the first and second pulleys (17, 20) for guiding the movement of the flexible endless means around said pulleys (17, 20) and for tensioning said flexible endless means (22) and that the flexible endless means (22), the pulleys and means for tensioning both runs of the flexible endless means (22) are arranged in one plane.
Slide door operating system according to claim 16, characterized in that said tensioning means are arranged in the space encircled by the endless flexible means (22).
Slide door operating system according to claim 16 or 17, characterized in that said tensioning means include biasing means biasing said tensioning means against said flexible endless means (22) to softly tension the flexible endless means such as to allow for limited manual displacement of said slide door (3).
Slide door operating system according to one of claims 16 to 18, characterized in that the drive device comprises a guide rail (2) secured to the vehicle body (1) while the first and second pulleys (17, 20) are arranged at spaced positions beside said guide rails, a bracket (4, 23), secured to said slide door (3), having an end by which said portion (23a) of said flexible endless means (22) is grasped, and auxiliary guide means (33) mounted on said vehicle body (1) between said first and second pulleys (17, 20) for guiding the movement of said flexible endless means (22).
Slide door operating system according to one of claims 16 to 19, characterized by means for providing a meshed engagement between each of said first and second pulleys (17, 20) and a flexible endless means being an endless belt (22).
Slide door operating system according to one of claims 16 to 20, characterized in that said tensioning means comprises two tensioners for tensioning said endless flexible belt (22).